You can watch the movie. And twice. To identify clues.
Although I guessed in the middle of the movie. I love watching apocalypse movies. The best film on the subject for me is The Burden, starring Martin Freeman.
And now Spoilers!!!
Not reading who hasn't seen the movie.
Yeah, so much loved, and so beloved to her is everything in this life that it extended his life for about 40 years, feeding him human, fresh meat every day. How many people did you have to kill? No, well, she let him go in her old age, giving him the chance to, like, eat her. And taking on the bloody hands, we went. .
Why didn't you do it before?
It's a pity for Kai's family to give shelter to this couple.